单片机C51 8位流水灯

#include<reg51.h>
sbit P1_0=0X90;
sbit P1_1=0x91;
sbit P1_2=0x92;
sbit P1_3=0x93;
sbit P1_4=0x94;
sbit P1_5=0x95;
sbit P1_6=0x96;
sbit P1_7=0x97;

void stop(void);
void delay(unsigned int xms);
	
int main(void)
{
	int i=2;
	P1=~0;
	for(i;i>0;i--)
		{
					P1_0=0;
			    delay(500);
			    P1_0=1;
			    delay(100);
				  P1_1=0;
			    delay(500);
			    P1_1=1;
			    delay(100);
					P1_2=0;
			    delay(500);
			    P1_2=1;
			    delay(100);
				  P1_3=0;
			    delay(500);
			    P1_3=1;
			    delay(100);
				  P1_4=0;
			    delay(500);
			    P1_4=1;
			    delay(100);
				  P1_5=0;
			    delay(500);
			    P1_5=1;
			    delay(100);
				  P1_6=0;
			    delay(500);
			    P1_6=1;
			    delay(100);
				  P1_7=0;
			    delay(500);
			    P1_7=1;
			    delay(100);
    } 
		stop();
		return 0;
}
void stop(void)
{
	while(1)
	{;}
}
void delay(unsigned int xms)
{
	unsigned int x,y;
	for(x=xms;x>0;x--)
	   for(y=110;y>0;y--);
}